HELP with fuel flow of mainsail

[superm18]

Hi all,

I'm launcing an interplanet tug in one go. i'm used to a circular-asparagus like this:

but find that with payloads that BIG it tends to wobbel spin or something else, so i started using square-asparagus like this:

but somehow i cannot explain the difference in fuelflow on the mainsail's! they consume different amounts of fuel and therefor the waight ballance gets worse and the stages dont match in symetry!

I checked the fuellines again and again and i'm pulling my hair out any second now! plz help!!

here's the craft file:

http://www./download.php?tt5ret3gdcq2l12

[superm18]

on a side note...i allways put the fuellines at the bottom and this is the first time i set them at the top, but moving all of them didn't help!...also i've tryied different stage-setup but still the same problem with fuelflow!

[SpaceshipFood]

having fuel-lines to begin with is what is causing the imbalance.

[superm18]

what are you saying? that i can't use fuellines

[Bashkire]

It's just a suggestion, but try going back to the circular shape, but disable the gimballing on all the engines apart from the centre one. It might be that your rocket it turning and oscillating because all the engines are over compensating for every twitch the craft makes in ascent.

[Sir Nahme]

I've had this issue with a rocket one launch and not the other. It's a bug I believe that I haven't been able to duplicate.

[Francesco]

don't use ASAS

[leopardenthusiast]

Try it with fuel lines at the bottom. As a general rule, you should only put fuel lines at the top if you only have one tank per engine.

[Flixxbeatz]

Managing fuel flow with massive core stages is totally messy. Also, I've noticed that fuel now only flows from one tank and receives from another, no matter how many fuel lines have been put to/from the tank.

Or you could just drain fuel on the tug (or construct detachable engine setup connected to the payload to get the surplus propellant useful) and just fill it later. That would reduce the payload weight (or give you extra OOMPH during liftoff with extra engines).

[superm18]

My problem is NOT wopple, spin or anything like that...if you tryed the craffile you would see that it flyes straight(press 0(zero)to disable gimbel on the engine that matter)

My problem is that each mainsail engine uses different amounts of fuel, so that the stages becomes unequel!...i tryed with the fuellines at the bottom...

[Shuttle]

I've experienced the same bug (?) myself but it was not so critical: in my case some mansails shut down ~10 seconds before the others. One of my vessels flipped over shortly after lift off but that was only because I put fuel lines on one side of the rocket and forgot to put them on the opposite side.

[HGGundamReviews]

I have had a problem like this but with smaller launchers. I use 5 mainsails but only burn 4 with 4 smaller engines burning with the 4 lit mainsales on their own fuel stacks. For the smaller stacks I run 2 lines out of the bottom into the mainsail stacks (one line to each stack on each side) This ensures the smaller stack burns out first and the 4 mainsails stay full till the 4 smaller stacks drop. the 5th mainsail is attached to the center stack and only burns when the rest have dropped. I tried running lines into it from the 4 big stacks but it caused the tanks to burn unevenly and I would flame out a single engine before the others, which in turn caused death, destruction and a very pretty light show for the folks on the ground.

I'm not sure how to do a similar arrangement with this large a setup though O.o

[Akalaël]

I had a similar problem and discovered it came from a docking port.

The fiuel was drained from my upper stage to a random bottom tank. Just clicking on "Disable Crossfeed" solved the problem.

Do you have docking port in your huge thing ?

[HoY]

I'm not on my computer or I would check myself, but is there a chance that your very first set of tanks and engines has TWO fuel lines coming out of it leading to two different pairs of engine/tanks?

[superm18]

I had a similar problem and discovered it came from a docking port.

The fiuel was drained from my upper stage to a random bottom tank. Just clicking on "Disable Crossfeed" solved the problem.

Do you have docking port in your huge thing ?

yes i have a tricoupler with dockingports between payload and lifter...but the payload has no active engines

[superm18]

I'm not on my computer or I would check myself, but is there a chance that your very first set of tanks and engines has TWO fuel lines coming out of it leading to two different pairs of engine/tanks?

i think you found the problem!! i have two line comming out of the first stage, wich is the 4 stacks in the corner's

[HoY]

I ran into the exact same problem with someone else's large mother ship launch stage, I forget his name but his ship was called the Zues. The two pairs of engines drawing from the single location isn't handled properly in ksp, the tank can only take one request for fuel at a time so the delay between request handling means the engine that is second in line will have to burn fuel from somewhere else first before its given its requested fuel through the pipe

The way I solved it was to add another set of tanks and engines stuck directly onto the side of the first stage set, and didn't use a decoupler. Now I piped from the new stack to the other half of stage two.

Poorly explained, but if you need some help understanding it I can try again lol

(It's really late at night !!)

Here it is. Notice when the very first stage drops its two pairs of tanks and engines stuck together.

Launching, Partially Orbiting, and then Re-Entering the Zeus Mothership.

[Akalaël]

yes i have a tricoupler with dockingports between payload and lifter...but the payload has no active engines

It does not matter if you have engines or not on your playload, if you have a link between the playload and your launch stage, then the fiuel is drained...

Be sure to cut off the crossfeed, or add a decoupler to prevent this.

[HoY]

It does not matter if you have engines or not on your playload, if you have a link between the playload and your launch stage, then the fiuel is drained...

Be sure to cut off the crossfeed, or add a decoupler to prevent this.

Docking ports connected via tri couplers do not cross feed fuel the way you'd expect. You can transfer fuel through them but they won't cross feed on their own. In short, no need to disable cross feed and this isn't the cause of his problem

[superm18]

It does not matter if you have engines or not on your playload, if you have a link between the playload and your launch stage, then the fiuel is drained...

Be sure to cut off the crossfeed, or add a decoupler to prevent this.

Okey, but there is a decupler between the lifter and the tricoupler

[superm18]

I ran into the exact same problem with someone else's large mother ship launch stage, I forget his name but his ship was called the Zues. The two pairs of engines drawing from the single location isn't handled properly in ksp, the tank can only take one request for fuel at a time so the delay between request handling means the engine that is second in line will have to burn fuel from somewhere else first before its given its requested fuel through the pipe

The way I solved it was to add another set of tanks and engines stuck directly onto the side of the first stage set, and didn't use a decoupler. Now I piped from the new stack to the other half of stage two.

Poorly explained, but if you need some help understanding it I can try again lol

(It's really late at night !!)

Here it is. Notice when the very first stage drops its two pairs of tanks and engines stuck together.

Okey that makes sense ill try when i get home

[superm18]

I finally did it thanks for all the help!!

the setup ended like this:

green= gimbeling engines

red= non-gimbeling engines

and the core (thw white center) like this:

Thanks again for all the help!!